Thermionic tube and circuits



Filed Jan. 14, 19556 l0 SheatsmSheet l Nov. 29, 1938. C. wQ HANSELL 2,138,162

THERMIONIC TUBE AND CIRCUITS Filed Jan. -14, 195e 1o sheets-sheet :5

6mm HECHO M7465 can/mm fzfcmaf M7465 ATTORNEY Nov. 29, 1938. c. w. HANSELL THERMIONIC TUBE AND CIRCUITS Filed Jan. 14, 1936 l0 Sheets-Sheet'4 IIIIVVI'VIVIVVVI '11111 INVENTR 'I VVVVVVVVV nu nAnAnnnA c. w. HSELL AII'TORNEY Nov.i 29, 1938.. c. w. HANSELI.

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THERMIONIC TUBE AND CIRCUITS Filed Jan. 14, 193e 1o sheets-sheet e RESOA/A/V MIE lNVENTOR C.W HANSELL A'TORNEY Nov. 29, 1938.v c. w. HANsl-:LL

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THERMIONIC TUBE AND CIRCUITS Filed Jan. 14, 1936 10 SheetS-Sheet 9 70M? CONVERTER INVENTOR '4M/L CLVV. HANSELL l ATTORNEY c. w. HANsl-:LL 2,138,162

THERMIONIC TUBE AND CIRCUITS I Filed Jan. `14, 195e. 1o sheets-sheet-lo Nov. 29, l938.

Patented Nov. 29, 1938 UNITED STATES Y,'rntERlvnoNIc TUBE AND CIRCUITS Clarence W. Hansell, Port J eifel-son, N. Y., assignor to Radio Corporation of America, a corpora tion of Delaware Application January 14, 1936, Serial No. 59,054

52 Claims.

Ihis invention relates broadly to a new and improved thermi'onic tube of the cathode ray type and to new circuits for generating, rectifying, relaying, amplifying, frequency multiplying, demodulating or modulating `alternating currents of any frequency.

A specific object of the present invention is to provide a new tube of the type described which is particularly adapted to generate, relay, amplify or frequency multiply or demodulate or modulate or convert from one frequency to another modulated or unmodulated ultra high frequency currents and to perform substantially all other services for which known thermionic tubes vmay be used. In addition my new tube makes possible the performanceof other functions for which previously known tubes are unsuitable.

A further object of the present invention is to provide new and improved circuits for use with tubes of the type described in the preceding paragraphs when operating at ultra high frequency.

In general, tubes known heretofore are limited in their application in various respects. They have denite upper frequency limitations at which the inter-electrode capacity in effect provides a low reactance shunt across the impedance between the elements thereby preventing the building up of substantial potential difference between the cathode and grid or anode and grid. Moreover at ultra high frequency the grid potential reverses in a time period less than the time required for the electrons to travel from the cathode to the grid. Consequently the tube is .,deflected laterally and thereby caused to im- `pinge to a varying extent on one or more suitably positioned anodes. Thus the action of the tube does not depend on the rate of ow of the electrons from the cathode to the control grid.` l However, in this latter tube low efficiency in operation of the cathode results from the nature of the cathode and its arrangement with respect to the other electrodes. In such tubes a rather small percentage of the electron emission is used Vin producing useful output from the tube. `This (Cl. Z50-27) latter defect is in general present in nearly all other cathode rayl type tubesknown and represents one of the main disadvantages attendant on the use of such tubes.

An object of the present invention is to provide a new tube of the cathode ray type which is less limited as to frequency by the rate of flow of the electron streamufrom thecathode to the control grid. i

Another object of the present invention is to 10 provide a new and improved tube of the cathode ray type as described in the preceding paragraph in which the` electrodes are arranged ina novel manner to obtain the utmost use of the electron stream. In this manner, high eiciency and high electron current are obtained.

The novel features of my tube and of various circuits in which said tube may be utilized have been pointed out with particularity in the claims appended to this specication.

The nature of my novel tube and the mode of operation of the same and of the circuits connected therewith will be better understood by the` following detailed description and therefrom when read in connection with the drawings through which like reference characters indicate like parts and in which Figures 1, 2, 4 and 5 show, for purposes of illustration, various modifications of my novel tube structure;

Figure 3 illustrates by curves the operation of the tubes of my invention; y

Figures 6 to 12.inclusive illustrate novel circuit arrangements by means Vof which the novel tubes of the preceding figures may be utilized to'V relay, or frequency multiply alternating current potentials or direct current pulsations;

Figure 12m illustrates a circuit arrangement wherein the novel tube of my invention is connected in a novel circuit and coupled to a source of oscillations to produce oscillations of increased frequency;

Figures 13 to 17, inclusive, disclose novel circuits for utilizing my novel tube to demodulate oscillations. The oscillations may carry signals and may be of any frequency. The demodulation may be accomplished' by a simple rectifying action orV by the use of local oscillations for heterodyning purposes;

'Figures 18 to 23 illustrate the use of my novel tube in novel circuits arranged to produce sustained 4oscillations of considerable amplitude and substantially constant frequency.

In Figures 18 to ,23, inclusive, regeneration is produced between the anode circuit and the accelerating electrode circuit.

In Figure 23, the frequency of the oscillations produced is controlled by means of a resonant, low -power factor line;

Figures 24 to 29, inclusive, illustrate the use of my novel tube in novel modulation circuits;

Figure illustratesthe manner in which the novel tubesof my invention may be connectedin.

novel phase modulation circuits;

Figure 31 illustrates diagrammatically a novel. tone converter circuit utilizingthe novel tubes of my invention;

Figure 31a. shows diagrammatically a keying circuit wherein keyed tone signalsare converted into impulses which in turn modulate the oscillator for signalling purposes;. 1

Figure 32 illustrates diagrammatically' the es` sential elements of a novel transmitter: circuit. incorporating the tubes of my invention; while Figure 33 shows diagrammatically a novel circuit arrangement wherein a thermionic tube of Y the present' invention controlsithe amplitude of a radio frequency amplifier in a novel fashion in accordance with the intensity of signals characteristicof the Ysignals impressed on the amplier.

lReerringV to the drawings and* in particular to Fig. 1 thereof, 2 is a low voltage high current cathode axially located with respect to an accelerating and control electrode 4 which as shown has an inner-periphery relatively close to one end of the cathode 2 and an outer periphery which is relatively widely spaced from the cathode Y2. 'I'he intermediate portionsv of the accelerg ating and control electrode 4 recede from the cathode as shown from the inner-periphery to the outer periphery thereof. The cathode 2 is supplied as shown with heavy heating current through heavy leads L coaXially with the cathode which may be connected as shown to a source of cathode heating current. The anode 6 is located coaxially with respect to the heating leads of the cathode and is separated from the electron emitting portion of the cathode by a disk-shaped portion 'I arranged as Shown. The anode may be maintained at the desired direct current potential by'connecting the same as shown to the positive terminal'of a source of potential.

The arrangement as shown causes electrons leaving diierent points along the cathode to be accelerated at diiferent rates by the control electrode 4-'andto acquire diiTerent velocities in their travel from the cathode toward the anode. Those leaving the end of the cathode near A acquire a higher velocity than those leaving the cathode near the point B. 'Ihe velocity which may be imparted to the electronsrmay decrease progressively from the point A to the point B and may decrease at various rates as desired by properly shaping the accelerating electrode 4.

Due to the large cathode current, which should be derived from a constant direct current source, a magnetic field exists around the cathode and its end connections. This magnetic eld delects the electrons drawn out from the cathode toward the anode, if thecathode current is in the correct direction.. Those electrons having high velocity travel a relatively long path in the magnetic iield, while those having a low velocity, travel a relatively short path. As a result when the tube is arranged in accordance with my invention, all electrons leaving the cathode at one instant strike the cathode stem 'I or the anode 75# ul at substantially the'same later instant. Moreover, in the arrangements shown all electrons leaving from different points along the cathode between points A and B tend to strike the cathode stem at the right of B, or the anode, at the same instant. In other words, in my novel tube there is a strong focussing of the electron stream on a ring enclosing the cathode lead, which may be selected at will. The location of the ring on which the electrons are focussed isla.l function of the intensity of the electron stream, the potential ofi the anode, and of the energizing and shaping of the electrodes, and in particular of the accelerating control electrode 4.

The electronfilow has been indicated diagrammatically'by the shaded areas in Fig. 1. 'Ihese areas.inxparticularrrindicate the outside limits of the electron path in their passage from cathode to anode orfrom cathode to the cathode stem. vThe shaded areas III) which come to sharp points on the anode are intended to show a cross section of the volume occupiedby moving electrons when the anode current is a maximum. This condition' is attainedl principally by applying a predetermined potential between 2 and 4. The overlapping shaded areas I2' whichv come to sharp points on the shield I on the'cathode-stem are intendedv to show a cross-section of the volume occupied by moving electrons when the anode current is zero. This condition-is attained-when theV potential on 4' is made less positive relative to 2.

By varying the potential between the accelerating control electrode 4 and the cathode 2, the position at which the electrons strike the anode or return to the cathode stem or to the shield I on the cathode stem may be varied. Therefore, the current flow to the anode may be controlled by simply varying the potential between the con trol electrode and cathode or by varying' the anode potential or both. It may also be controlled by varying the cathode current in any manner to vary the magnetic field but in the present application I prefer-to use* variation in electric forces instead.

By adding annular shields 1'v and I4 to the cathode stem as shown in Fig. 1 on each side ofA the anode, the electrons may be shielded-from the electriceld of the chargedl anode during most of their flying time and variations in anode potential'will have little effect upon the anode current. This results in a high anode impedance similar to that of shieldl grid tubes of the type already' known in the art and gives a high amplification constant without requiring flow of' current to the control electrode during peaks of anode current.

Obviously the electron current may also be made to fall upon the shield I4 by making the potential of 4 sufficiently positive with respect to 2. By making adjustments for varying the electron current between shield I4" and anode 6 the alternating current polarity ofthe tube output is reversed to what it would'be when the electron current is varied between shield 'I and the anode. My novelcathode raytube maytake manyforms. For example, the tube may be arranged as indi- A cated in Fig. 2. In Fig. 2, one end of the cathode terminates in a conductive disk 9 as shown. 'Ihe disk 9 serves not only to supply heating current to the cathode but also as a shield between two chambers within the tubeenvelope. One chamber includes the input electrodes which are to be connected to 'the input circuits, while the other chamber includes the output electrodes which are tobe connected tothe output circuits. This,v of

course, increases the stability of operation of the tube particularly when it is operated athigh frequencies at which shielding between output and input circuits isdesirable. Moreover, in Fig. -2 the anode 6 has a U-shaped cross section as shown. This reduces or eliminates flow of current from anode 6 to electrode 9 due to secondary emission from the anode when, inoperation-the anode potential may be negative with respect to electrode 9 during portions of the operating time.V

It should be noted in connection with the arrangements shoWn in Figs. 1 and 2 that by adjusting the control electrode potential above or below that required to give maximum anode current We may reverse the polarity of the alternating current output with respect to the alternating current input potential and current.- 'I'his feature is not possessed by ordinary tubes, though need for it is often met with in keying and signalling circuits. As an example, we may con-l vert from single circuit to pushpull circuit amplification, detection, etc., by feeding the inputs of two of the tubes in parallel while connecting their outputs in pushpull, provided we have the action reversed in the two tubes.

The principles of my new type vacuum tube may very well be applied toproviding more efi'lcient cathodes for all sorts of cathode ray tubes, including those in which Vthe brightness of the spot is modulated in addition to the spot being moved over a fluorescent screen (kinescope tubes). transmitting tubes such as Dr. Zworykins Iconoscope. i

To obtain some idea as to the correct dimensions to use in a tube suitable for receiving purposes I will assume that the control electrode and anode are each maintained at a positive direct current potential of about 135'volts with respect to the cathode. The eifective diameter of the control electrode and twice the maximum distance electrons are to travel out from the axis of the cathode will be assumed to be .3 or 300 mils.

Then, for an approximate equation take Hulls equation I on page 915 of Transactions A.v I. E. E.,

V01. CLII, 1933, Which ist E=.0188I2(log10 D/d) 2 where E=voltage.

I=cathode current in amperes.

D=diameter of anode (in this case effective diameter of accelerating and control electrode).

dzdiameter of cathode.

Substituting in this equation We get:

or better yet use I-Iulls Equation 2, which assumes a cathode temperature of 2500 K., then:

The values of E for various assumed values of d They may also be applied to television would be required for a control electrode having an effective diameter of about 0.3 inch.

If we assume D=0.6 inch then the control electrode voltage for various cathode diameters will be:

Mls Volts vention and includes a 40 mil filament having an active length of .5 inch in combination With a control electrode of 1 inch eifective diameter, We would obtain in the ideal case a peak anode current of .5 ampere and in doing so we would use a direct current control electrode potential of 90 volts. With 90 volts on the anode we might obtain a maximum alternating current output ci about 2.5 watts. By raising the anode potential we should obtain about 25 watts at 900 volts and 250 watts at 9000 volts. The lament power required Would be about 150 watts. The power and voltage gain obtainable will be very high in my new tube. y

Since very heavy cathode current is objectionable in receiving tubes other means in addition to those shown in Fig. 2 for focussing the electron stream on the anode or target besides the magnetic field is desirable. Such a focussing and electron timing scheme has been shown in Fig. 4. In this gure the tube comprises a control electrode 4 and indirectly heated cathode 2 having a radially enlarged shielding portion 5 as shown. The cathode 2 and control electrode :t are separated from the anode by a shield and accelerating electrode 9. Annular openings are provided in the shield 9 to permit the electron stream, when properly focussed, to reach the anode 6. The anode 6 is, as in Fig. 2, U-shaped in cross section. This shaping of the anode minimizes the effect of secondary emission by reducing the possibility of potential gradients Where sec-- Ondary. emission is produced by primary electron impacts upon the anode surface and so preventing the secondary emission produced from reaching the other electrodes. The diaphragm electrode 9 is preferably charged `to a more positive potential than the accelerating and control electrode it. Preferably the diaphragm S is brought outside the glass envelope of the tube as shown to provide a continuation of the metal partition between the two shielded compartments in the tube. The continuation of the diaphragm 9 may also serve as the mounting for the tube upon the metallic shield I8, which eiectively isolates the input circuits from energy' feed back from the output circuit.

In the operation of the tube electrons leaving the lament are first acted on chieiiy by an electric field due to the control electrode 4. The force is greatest on electrons leaving the cathode from points farthest from the anode. This is due to the shield on the end of the cathode and the size,

shape, spacing and potentials of the other electrodes. After the electrons leave the cathode they come more and more under vthe influence of the electric field produced -by the :diaphragm electrode potential and this bends the electron paths in approximately the same way as the magnetic field in the tubes of Figs, l and 2. I so arrange, shape and energize the electrodes that all electrons leaving the cathode arrive at the diaphragm electrode 9 at nearly. the same radial distance from the axis of the tube. Moreover, the electrons leaving the cathode at the same instant arrive at the diaphragm at nearly the same later instant and consequently are concentrated on the anode at the same instant.

The areas I6, enclosed by the dotted lines, in Fig. 4 represent the electron pathsfor the condition of maximum anode current. For other control electrode potentials than that assumed in Fig. 4 the electrons would miss the openings in the shield 9, which also acts as an accelerating electrode, partially or altogether and so reduce the anode current to any desired value between maximum and minimum.

By varying some of the electrode potentials the distance from the axis of the tube at which the electrons arrive at the diaphragm electrode 9 may be varied. Consequently the electrons may be made to strike either the diaphragm 9 or the openings in it accordingly to the electrode potentials. If they strike the openings they will, of course, land on the anode and produce an anode current. Consequently we may control the anode current by varying the control electrode or cathode potential `with respect to the diaphragm, or we may vary both. I prefer to vary only the control electrodeA potential in most cases.

In Fig. 4 I have shown' openings in the diaphragm 9 of considerable axial length so that there will be little potential gradient inside these openings. This reduces the forces acting on secondary emission electrons and reduces the secondary emission from the diaphragm which can arrive at the anode.

Of course, my novel tube is applicable to all classes of signalling including transmitting as well as receiving. Where large powers are to be handled I contemplate cooling one or more of the electrodes of the tube. For example, as shown in Fig. 5 the anode electrode 6 of the tube may be cooled by a circulating fluid. The cathode I is somewhat similar to the cathode 2 of Figs. 1 and 2. Here, however, the cathode terminatesqin a radially expanded portion 5i which is continued axially as shown at 5 to form a shield for the cathode 2 and for the accelerating electrode 4. This axial portion 5 may also serve as one of the leads L for applying the heating current to the cathode. The radial portion of the shield has openings therein as shown through which the electrons may reach the anode 6. The magnetic field from the cathode current deects the electrons as in the tubes of Figs. 1 and 2. The dotted lines in the upper half of Fig. 5 show the condition of maximum anode current while those in the lower half show a condition of zero anode current. Another condition of zero anode current can be obtained by increasing the positive control electrode potential to make the electrons strike outside the openings in 5.

The tube of Fig. 5 may, of course, normally be used with a fluid cooled output circuit inductance or coil of copper tubing through which water may be circulated to the anode as disclosed in Moser,

US. Patent #1,857,029,May 3, 1932. See also Hallborgs U. S. Patent #1,963,131, June 19, 1934. Although I have shown an anode made of metallic tubing with a cylindrical cross section area it will `be understood that the tube may have other shapes. If the tubing has a disk shape or U-.shaped cross. section such that the electrodes strike the anode in a depressed area as they do in Figs. 2 andil secondary emission will be reduced and the effect of that which takes place will be reduced.

Since to obtain high efliciency in any of the tubes in theforegoing figures as an oscillator or class C amplifier, we must drive the anode potential `down almost to Zero when anode current ilows, we must provide for the condition where the anode potential is below the diaphragm potential. This requires suppressing the effect of secondary emission from the anode. The anode in my tube is so shaped as to give very low potential gradient where the initial electrons strike. 'This reduces the secondary emission current which can flow back from anode to diaphragm. Preferably a carbonized anode, or anode of material selected to minimize secondary emission, is.used.

The tubes of the present invention may be utilized for any purpose for which any known types of vacuum tubes can be used and, in addition will perform functions for which other known types of tubes are unsuitable.

When it is desired to relay or amplify alternating current potentials or vdirect current impulses of any frequency, with circuits similar to` those shown in Fig. 1, the said impulses may be applied to the leads marked input, connected to the primary Winding of .a transformer. 38, the secondary winding of'which is coupled as shown between the control and accelerating electrode 4 and the cathode 2. The last named connection may, if desired, be by way of a by-passing condenser C. The secondarywinding of the transformer may be tuned to the frequency of the oscillations or impulses to be relayed if desired by a variable condenser 3l connected as shown. The relayed and amplified oscillations impressed on the input electrodes are repeated in the tube in the manner described hereinbefore and caused to appear on the anode electrode from which they may be set up in an output circuit including a primary Winding connected as shown between the anode 6 and the cathode 2 by way of a second -ley-passing Condenser C. This primary Winding of transformer 32 may be tuned by a variable condenser 33 connected as shown. The oscillations appearing in ythis tuned circuit may be impressed on the secondary winding coupled thereto and transferred from said winding to any utilization circuit by way of the leads marked output,

The anode electrode may be connected as shown to a positive point on a source of direct current potential, the negative terminal of which is connected to ground and to the cathode. The control electrode and accelerating electrode d may be maintained at the desired potential with respect to the cathode .by connecting electrode 4 to a separate source of potential or to the desired point on the first named source'. The sources of potential may be :a battery or a lter network connected with a rectifier.

In the description of the novel circuits in which my novel tube operates, which follows, the tube has vbeen' shown somewhat schematically.

'I'he tube of each of the circuits may be the tube shown in Figs. 2, 4 or 5.

Many other circuits may be utilized With the novel tube of my invention. For example, as shown in Fig. 6, the potentials to be amplified maybe impressed on the primary winding of a transformer 30, the secondary winding of which is connected as Vshown to the control and accelerating electrode 4 and by way of a potentiometer resistance 34 to the electrical center of the cathode heating circuit. If the cathode is insulated from the cathode heater, as is *done in some known types of tubes, the connection will be to the cathode rather than to the center of the heating circuit. The cathode heating circuit here is assumed to be connected with an alternating current source of potential and the cathode -may be of the directly or indirectly heated type. The accelerating and shield electrode 9 may be connected as shown to a point on the potentiometer resistance 34. The anode electrode is connected by way of the primary winding of a transformer 32 to an additional point on the potentiometer resistance 34. The oscillations or impulses to be amplified are shunted around the source and across resistance 34 by way of by-pass condensers C, C' and C connected as shown between the cathode and the Various leads between the other electrodes of the tube and the potentiometer resistance 34. To reduce voltageY variations the potentiometer may be made up of material having selfregulating resistance, such as Thyrite, or of series connected glow discharge voltage regulating tubes or similar devices. See my U. S. application Serial No. 710,235, filed February 8, 1934, now Patent #2,086,910 dated July 13, 1937.

In operation, the electrons are concentrated on the shield 9 or the openings therein. As the potential on 4 swings due to the varying potentials from 30, the distance from the aXis at which the electrons impinge on 9 swings radially. The anode current flow waxes and wanes directly or in a reverse sense at the frequency of the applied potentials. Whether the anode current follows the applied current or is reversed with respect thereto depends on the magnitude of the direct current potential between 2 and 4 and between 2 and 9.

In Fig. 6 it has beenassumed that low frequency impulses or alternating currents are to be amplified and ironor alloy-cored transformers have accordingly been shown. Of course, where higher frequencies are involved the transformers may be air-cored and the windings thereof may be tuned to resonance at said frequencies where desired.

The input circuits of the amplifier of Fig.` 7 are somewhat similar to the input circuits of the amplier of Fig. 6. The emission and control of said emission is similar to that of the tube and circuit of Fig. 6. However, in Fig. 7 the shielding and accelerating electrode 9 serves as the anode electrode connected with the output transformer 32, while the anode electrode 6 is maintained at a less positive potential and is connected as shown to a point on the potentiometer resistance 34. In this arrangement the fluctuations of the shield potential resulting from the-.amplifying action may be made to add to the amplifying action of the tube or to oppose the same depending upon the adjustments of electrode potentials. The tube and circuits are regenerative when a change in shield potential will change the shield current in a direction to increase the change in potential. The regeneration may be carried to a point at which sustained oscillations are produced. The amount of regeneration maybe controlled by controlling both the potential adjustments and the losses in the circuits, or by introducing and varying a coupling between output and input circuits.

In the arrangement of Fig. 8 the anode electrode 6 and the shielding and accelerating electrode 9 both serve as output electrodes. I-Iere.-`

as in Fig. '7J the fluctuations in potential of the acceleratingshield electrode 9 may be used to cause a regenerative effect and to add to the fluctuations of the anode potential or the potential fluctuations of ll/and 6 may be made to oppose each other to the, desired extent. The opposing effects may be equal or may produce degeneration or regeneration to such an extent as to produce oscillations at almost any frequency. Here again it is assumed that low frequency oscillations or'impulses are` to be amplified with the specific arrangement shown. The circuit is,

of course, applicable to the handling of high frequency oscillations. In the latter case air-cored tuned transformers may be utilized where desired.

An arrangement for amplifying or frequency multiplying high frequency oscillations is shown in Fig. 9. 4The circuit arrangement of Fig. 9 except for the air-cored transformers and tuning condenser?! and the tuned output circuit 39, is somewhat similar in arrangement and operation to the circuit of Fig. 6. In Fig. 9, however, the voutput lenergy is supplied from a point on the inductance in the output circuit to any load circuitby way of a coupling condens- The' push-pullsarrangement of Fig. 10 comprises aradio frequency push-pull input circuit transformer 30 including a primary windingl which may be connected to the source of oscillations to be amplified and a secondary winding connected as shown atits terminals to the electrodes 4 and at a point intermediate its terminals to ground and from ground to the cathode vor to the electrical center of the tube cathode heating circuits. The anode electrodes are connected ras shown in push-pull relation by way of a tuned circuit 39, a point on the inductance of which may be connected by way of a blocking condenser 36 toV a utilization circuit. The shield? ing and accelerating electrodes 9 may be maintained at'the desired potentials. This circuit may be used either as a push-pull amplifier or as a frequency multiplier for producing odd harmonic multiplication. vIn the lformer case the secondary winding of the transformer 30 and .the tuned circuit 32 are tuned to the fundamental'frequency while in the'latter case said winding and circuit are tuned to the fundamental vand the odd harmonic to be selected respectively.

In the arrangement of Fig. 11 oscillations from the source to be amplified are applied as shown between a capacity 38 and ground. The free terminal of the capacity 38 is. connected as shown to a point on vthe inductance of circuit 40. The

.while `the anodes are connected in push-pull by lcircuit 39H. Y. The circuit as `shown may be used as circuit including a tuned reactive circuit 46 and the lay-passing condenser C". By tuning the circuit in the appropriaternanner, regeneration or degeneration on any desired input or output frequency may be insured; Moreover, regeneration may be carried to such an extent as to produce oscillations in the circuit 9, 4E for heterodyning with the incoming signal modulated wave to produce in the output circuit of the demodulator an intermediate frequency. In the latter case, the iron core transformer l32 may be replaced by a transformer or reactance, tuned by means of a condenser, which will Voperate efflciently at the intermediate frequencies. l

In both Figs. 15 and 1'7 the two inputs may have a small difference in frequency in order that their combination may produce beats which can be detected or rectified in the tube to make the beat frequency audible. This is equivalent in resuits to the well known heterodyne dectector for continuous waves. Alternatively the two inputs may have a difference in frequency above audibility in which case the'beats will also be above audibility and correspond .to the detection which takes place in the first detector of a superheterodyne receiver.

When it is desired to generate oscillations, an arrangement as shown in Fig. 18 maybe utilized. Here, the filament may be heated by a circuit ccnnected. as shown in the preceding gures. A tuned oscillatory circuit 45 may be connected as shown between the controlling and `accelerating electrode 4 and the electrical center'of the filament heating circuit byway of ground and condenser C. The anode electrode 6 may be coupled to an inductance 41 variably coupled to the inductance in the tunedcircuit 45. When proper potentials are applied to the electrodes 4, 9 and 9, sustained oscillations will be produced in the tube and circuits 45, 41 and said oscillations may be supplied to any utilization circuit by way of a coupling condenser 48, connected as shown to the anode 6. High frequency oscillations appearing in the circuit 45 and in inductance 41 and on the shielding electrode 9 may be by-passed around the potential sources by way of by-passing condensers C, C' and C", connected as shown.

The oscillator shown in Fig. 19 is similar in many respects to the oscillator shown in Fig. 18. In the oscillator of Fig. 19, however, a tuned anode circuit 49 is utilized and is variably coupled to an inductance 59 connected with the controlling and accelerating electrode 4.

In the oscillator of Fig. 20, va tuned` oscillatory circuit 45 is connected between the accelerating electrode 4 and the cathode 2 and aY tuned oscillatory circuit 49 is connected between the anode and the cathode and coupled to thek first named circuit, thus inductive feedback coupling is providedA and oscillations may be produced with either polarity of feedback coupling provided suitable power supply potentials are applied to the tube.

Fig. 2l. shows an oscillation generator with a tuned anode circuit 49, tuned accelerating electrode circuit 45, and either capacitive or conductive feedback coupling, depending upon the size of the capacity 52 in the feedback circuit. Since the tube may be adjusted for either polarity of output with respect to input, by adjusting the bias on 1i, and the tuned circuits 45, 49 may be either exactly tuned or detuned in either direction from the frequency of oscillation, I may use either polarity of feedback. A switch SV vin -the feedback circuit is shown for reversing the feedback polarity.

Fig. 22 shows an oscillation generator with a Ytuned anode circuit 49 and tuned circuit 45 connected with the accelerating electrode 4, having feedback through a piezo-electric quartz crystal `PC for stabilizing the frequency. Undesired capacity feedback between the electrodes of the crystal holder may be neutralized by means of a neutralizing condenser NC connected as shown crystal and neutralizing condenser where they= tap on to the inductance in the accelerating electrode oscillation circuit 45.

The frequency of the oscillations generated by my novel tube and circuits may be stabilized as shown in Fig. 23, by a low power factor resonant circuit or transmission line 60, rpoints on which may be connected by way of movable taps to the tuned resonant circuit 45 connected with the accelerating electrode 4 and the tuned resonantA circuit 49 connected with the anode electrode V6. In this case, the polarity of the feedback may be Yreversed if desired by means of the reversing Yswitch S. 'Ihe resonant'transmission line may be asv disclosed in my U. S. application Serial No. 692,092, filed October 4, 1933 now Patent '#2,095,980 dated October 19, 1937. When the proper charging potentials are applied to the electrodes in the tube, oscillations are developed 'in the tubes and circuits and venergy is transferred from the tunedresonant circuit 49 to the low power factor circuit or line 69 and from the line to the tuned resonant circuit 45 to reinforce said oscillations and stabilize the frequency thereof. In a modification, the connections from the oscillatory circuits 4S and 49 may be made to the'A same end of the resonant circuit or transmission line B0. In this case, the line may be made sub- -stantially one-quarter wave length long or any Amultiple of one-quarter wave length long, and then feedback of sufcient amplitude and correct phase will only be obtained at the resonant frequency ofthe line. Al resonant low powerfactor linefor feedback and stabilizing purposes in an oscillatory generator has been disclosed in U. S.

application Serial No. 692,092, Filed Oct. 4, 1933:

110W Patent #2,095,980 dated October 19, .1.937.

When it is desired to modulate carrier wave oscillations, a circuit as illustrated in Fig. 24 may be utilized. In this arrangement, the high frequency waves to be modulated are applied by way of the ltuned circuit 45 between the accelerating electrode 4 and cathode 2. The modulating potentials may be supplied from any source by way of aV modulation frequency transformer 59 connected as shown to the shielding and accelerating electrode 9. The modulated high frequency wave Y will appear in the tuned circuit 49 connected with the anode 6 and may be supplied from said circuit by way of either anv inductive coupling or a coupling condenser 48 to any utilization circuit. In accomplishing modulation, regeneration or degeneration of the modulating energy may be accomplished by applying appropriate potentials v to the electrodes and in particular to the screening electrode 9 and anode 6 and by placing suitable impedances in the connections to the electrodes.

In the modification shown in Fig.-25, the modulating potentials are applied by the transformer 5S to the anode circuit and the modulated high frequency Wave may be supplied by the transformer 52 to any utilization circuit. Here, as in Fig. 24, high frequency oscillations. maybe bypassed around the power sources by way of bypassing condensers C, C and C" connected as shown.

In the modification of Fig. 26, the rmodulating potentials as well as the high frequency carrier Wave are applied to the controlling and accelerating electrode 4. The modulated wave may be supplied from the anode circuit, as in Fig. 24.

In the modification shown in Fig. 27, the high frequency wave is applied between a point on the induotance in the tuned circuit 45 and ground and from said circuit to the accelerating electrode 4 and cathode 2. The modulating potentialsare supplied by way of the secondary winding of a transformer 50 between the screening electrode 9 and the anode 6. In thisimanner regeneration at the frequency of the modulating potentials may be obtained by applying the proper potentials to the anode and screening electrode, thereby insuring a high input impedance into -which the high frequency'oscillations to be modulated may work.

In some cases, it may be desired to produce and modulate oscillations by means of a -single tube. In this case, a circuit arrangement as shown in Fig. 28 may be utilized. Here, the controlling land accelerating electrode yIl and screening electrode 9 are connected in voscillation producing circuits including the tuned oscillatory circuit The oscillations produced are modulatedin the anode circuit and supplied from the anode circuit by way of the transformer |52 to any utilization circuit. In order to prevent reaction of the anode and outputcircuit on the oscillation producing circuits, a neutralizing condenser 68 may be connected as shown between the anodeI and a point on the tuned circuit 60.

When it is desired to receive transmitted signals of anycharacter, I may utilizea receiving system as illustrated in Fig. 33. This system may comprise a receiving aerial H coupled to an amplier H2 which is in turn coupled to an amplifier H4. The output of the amplifier H4 may be connected to demodulate. on detector H6 and the output of said detector may be coupled to a lo-w frequency amplifier H8, the output of which may be coupled to any utilization circuit, as for example telephones. In order to control the output of the receiver and maintain the same relatively constant, irrespective of swings in the amplitude of the received wave, Icouple the amplifier H4 toa tuned circuit |20 coupled between the ,accelerating electrode ll and cathode of a thermionic tube. The anode electrode of the thermionic tube is connected as shown by way of a source |22 and a resistance |24 to the cathode of the tube. The resistance |24 may be connected as shown by wayof an automatic voluine control line AVC to the accelerating electrode `and cathode of one or more thermionic tubes in the amplifier I I2, to thereby control the gain of said amplifier tube in accordance with the potential drop in the resistance |24. The potential drop in the resistance |24 is in turn a function of the amplitude of the received signal. When the signal amplitude increases above normal, the gain of the amplifier I I4 is reduced and the opposite effect `is produced by a decrease in the receivedsignal amplitude. In practice the location of the source 22 may be changed or other anode circuits may be used.

The modification shown in Fig. 29 is similar to the oscillation generator of Fig. 28, except w that a piezo-electric quartz crystal PC has been included in the circuit connected with 4. In parallel With the crystal PC is an impedance 64, which supplies direct current potential to the electrode 4. The crystal on proper adjustment of potentials and circuits will stabilize the frequency of the oscillations produced in the selfoscillation circuit including the electrodes 2, 4, 9,

the piezo-electric crystal PC and the tuned cir-p cuit 60. Here, as in the modification of Fig. 28, the modulating potentials may be applied by Way of a transformer I) to the anode electrode 6 and the device may be neutralized by a condenser 68. The modulating potentials may be supplied to any circuit by way of coupling condensers 69 and 10.

In the arrangement of Fig. 30, my novel tubes are connected in a novel circuit to produce phase modulation. In this circuit, carrier Waves from...

a carrier wave source are applied by way of a coupling condenser to a phase retarding reactance IR 4and to a phase advancing reactance CR in combination with resistances R and R. The phase shifted oscillations from the reactances IR and IC are applied to the accelerating electrodes 4 of the thermionic tubes. Modulating potentials are applied in phase opposition .from any source byway of a transformer 'II to resistances R and R- and from said resistances.,

to the accelerating electrodes 4. In the absence of modulating potentials, both tubes supply substantially equal amounts of energy to the anode tank circuit 'I8 assuming like potentials are applied to the tube electrodes. will have a phase which is the average of the phases of the energies from two tubes. Now assume the tubes are modulated. One tube will supplymore energy to I8 than the other. The

phase of the energy in 'I8 will now change .and

approach the phase of the energy in the output of the tube supplying the most energy to 78. In this manner, phase modulated oscillations are produced in the circuit 18 and may be amplified in the push-pull stage 'I9 and appear in the tank` 'I'he energyin 'I8v act as a detector or converter for keyed or modu-" lated currents supplied from the transformer 'III to the accelerating electrode 4. The amplified energy appears inthe windings of transformer 'I6 and are applied in push-pull relation to the accelerating electrodes 4 of a pair of tubes 1|. These tubes have their anode currents controlled by the tone currents and impress energy characteristic thereof on resistors 'I8 and 'I9 connected with the anodes. If the input from 'I0 is a keyed tone signal, such as used to transfer messages over Wire lines, then the circuit shown may be made to have a reversing direct current output, the polarity of which will depend upon whether the signal is on or olf. The reversing direct current output may be fed to any apparatus for use in a repeating or recording system. 'Ihis sort of arrangement is often needed to 0D- erate keying relays, signal recorders, etc. An. on-off output, without reversing of polarity, may be obtained by using a single tube in the stage 1I.

In Fig. 31a I have shown means for impressing signals of any type, as for example, keyed tone oscillations or high frequency oscillations for transmission. The keyed tone signals may be impressed on the accelerating electrode 4 and cathode 2 of the tube from any source. The tube acts as a rectifier and rectified impulses characteristic of the signals are impressed by way of the modulation transformer 'I6 onto a modulation transformer MT onto a modulator and from said modulator onto an amplifier A and from the amplifier to a load circuit. Carrier wave oscillations may be supplied from a source connected as shown to the modulator.

In Fig. 32, I have tubes of the present invention connected in a novel transmitting circuit. This transmitting circuit comprises an oscillation generator in which the accelerating electrode 4 is regeneratively coupled by wayA of a piezoelectric crystal PC to the tuned tank circuit -92 connected with anode 6 in such a manner that sustained oscillations of a frequency determined by PC are produced when the electrodes are energized. The crystal has another electrode conwherein they are amplified and appear in the tuned tank circuit 98 connected with the anode 6 from which they are supplied in push-pull relation to the accelerating electrodes 4" of a pair of power amplifiers or modulators in an amplifying and modulating stage i90. The modulating potentials are supplied from a transformer to the accelerating electrode Illl of a tube in an amplifier stage |92 and from the anode ID3 of said amplifier stage to the accelerating electrode |04 of a tube in the modulator stage 06, This tube has its anode IUT connected to the anodes of the push-pull power stage 509 to accomplish therein anode modulation Aof the carrier waves. Note here that the use of my novel tube Ywherein the accelerating electrode may be charged positive permits this electrode tobe connected directly to the anode of the preceding tube as in stages 9D, 9B and |02, |06. The many advantages owing from this simplifying of the exciting circuits which permits the anode and accelerating electrodes of adjacent cascaded stages to derive their energy from the same source will be apparent to one skilled in the art.V

The stage 98 may operateY as an amplifier and as a frequency multiplier; Inthe latter case, the circuit 98 is tuned at a harmonic of the frequency of the oscillations produced in 90'. lated oscillations may be impressed on any utillzation circuit from the tuned circuit Ill) connected with the anodes 9" of the tubes in the stage |09.

Having thus described my invention and the operation thereof, what I Yclaim is:

1. A vacuum tube or valve, having in combination an elongated cathode lying in the axis of said The modutube, an accelerating and focussing control electrode adjacent one end of. said cathode and an anode, in which tube or valve the electron current from the cathode to the anode may be Varied by varying the potential of the control electrode.

2. A vacuum tube or valve, having in combination a cathode, an vaccelerating and focussing control electrode, an electron emission element, and an anode arranged in the order recited, a shield electrode adjacent said anode, the division of electron current in said tube to the anode and shield electrode being controlled by varying the potential of the control electrode or shield electrode or both.

3..A vacuum tube acccording to claim 1, in which electrons leaving differentl parts of the cathode at one instant of time all arrive at the anode at nearly the same later instant.

4. A vacuum tube according to claim l, in which said tube has a shield electrode between the anode and control electrode4 and in which electrons leaving different parts of the cathode substantially all arrive at the shield electrode at substantially the same distance from the axis of the cathode.

5. A tube as recited in claim 2, wherein said anode is fluid cooled.

6. A tube as recited in claim 1, wherein a magr netic eld at right angles to the axis of the tube is produced by current flowing in the said cathode to deflect the electrons from said cathode to said anode.

7. A tube as recited in claim 1, wherein the anode is cupped to reduce the effect of secondary emission.

8. A tube as recited in claim 2, wherein the anode is cupped to reduce secondary emission and said anode is fluid cooled.

9. In an 'electronic system, an elongated emission element which when energized emits electrons radially from the axis thereof, an accelerating electrode located adjacent one end of said emission electrode, and an anode located adjacent one end of said emission element, different points on the surface of said anode being different distances from said emission element.

10. A thermionicdischarge device comprising an electron system including an emission electrode, an accelerating electrode adjacent thereto, and an anode adjacent said emission electrode and an additional electron collecting electrode adjacent-said anode on which electrons may fall when the accelerating electrode is properly charged whereby the polarity of potentials on the anode may be reversed relative to the polarity of potentials applied to the accelerating electrode.

11. AV thermionic discharge device comprising an electron system including an emission electrode, an Vaccelerating electrode, ananode, and a plurality of collecting electrodes on opposite sides of said anode on which electrons may fall when the accelerating electrode is properly charged whereby the potentials on the anode may be in phaseor out of phase relative to potentials applied to the accelerating electrode. v

12. In an electron discharge device, an elongated cathode element which when energized emits electrons radially of the axis thereof, an anode located adjacent one end of said emission element, an accelerating electrode adjacent the other end of said cathode, points on the surface of which are located at differentV distances from said emission element, and means for energizing said accelerating electrode to thereby concentrate said electrons in a narrow path along the axis of 'said cathode which path may bevar'ied radially whereby alarge amount'of current conversion m-ay be obtainedf 13. In an electron discharge device an elongated emission element, an anode locatedv adjacent one end thereof, means for energizing said emission element whereby electrons are emitted radially therefrom yand driven toward said anode by the magnetic iield produced by energizing current in said emission element, means for accelerating the travel of said electrons toward said anode comprising anv accelerating electrode mounted adjacent the other end of said emission element, and means for energizing the same to produce an electric field.

14. In an electrical discharge device, means for producing adiifused electron'- emission, an anode, and meansfor imparting diierent rates of acceleration to Ytheelectrons of said emission .whereby substantially all of the electrons leaving the first means at a particular instant reach the anode simultaneously or at the same later instant. n

15. In an electrical discharge device, means for 25.l producing a diffused electron emission; an Yanode at one `side thereof, and an Yaccelerating electrode at the other side of said meansforimparting different rates of acceleration to the electrons of said emission to cause substantially all of the electronsleaving the first meansat' a particular instant toreach the anode at the same later instant. Y

16. In an electrical discharge device an elongated electron emission member, a cup shaped accelerating electrode adjacent one endthereof and a fluid cooled anode having a curved surface located adjacent'the other end thereof.-

17. In an electrical discharge'device an elongated electron emission member, acup shaped accelerating electrode-adjacent one end thereof, an anode, a cross section of which is U-shaped located adjacent the other end thereof, and a shielding and accelerating electrode interposed between saidanode and said-member.

18. An electrical `discharge-device comprising, an elongated heavy current cathode membena cup shaped accelerating control grid'at one end of said cathode, Ya fluid cooled anode coaxially located with respect to said cathode at the other end thereof, and a shield member connected to said cathode and interposed betweensaid cathode and said anode. Y Y

19. An electrical discharge Y device compris-` ing, an elongated heavy current cathode member, a curved annular accelerating lcontrol grid coaxially located at one end of said cathode, and a ring shaped anode coaxiallyY located with respect to said'cathodeatthe otherY end-thereof.

`ZOQA system comprisingan electrical Adischarge device having elongated linear means for producing emission of electrons, a charged member adjacent one endy of said linear means having a continuous surface the distance of ldifferent points on which froinsaid means Varies whereby the accelerationimpazjted' to the electrons from'said means decreasesy as the distance between said ,meansv and member increases, and an anode adjacent the other endof said elongated linear means. V Y

21. An electrical discharge device compris,-r ing an elongated heavygcurrent cathode member, a curved annular shaped accelerating control grid' located' at one endKA of said cathode, said'grids axisbeing on the axis of said cathode, and an'anode having a non-planar surface coaxially 'located at the other' end of said" cathode.

22. An electrical discharge devicecomprising, anelongated heavy current cathode member, a cup shaped 'accelerating and control grid electrode at one end of said cathode, a circular anode having a U-shaped cross section at the other end of said cathode, .and a shield member connected with said cathode and interposed between said cathode and said anode, there being openings in ,said shield member to permit the electrons leaving said cathode to reach said anode.

23. An electrical discharge device comprising, an elongated heavy current cathode member, aV curved annular acceleratingV and control grid electrode at one end of said cathode, an anode at the other end of said cathode, a shield member connected with said cathode and interposed between said cathode and said anode, and a second shield member conductively connected to said cathode and located on the side of said anode remote from said cathode.

24. An electrical discharge device comprising, an elongated heavy current cathode member, a cup shaped accelerating and control grid located adjacent one end of said cathode, a radially expanded shield member connected to the other end of said cathode, said shield member extending back along said cathode to enclose the same, and a shell-like anode located at the other end of said cathode.

25. A thermionic tube comprising, an elongatH ed cathodewhich when heated tends to produce radial emission, a cup shaped accelerating and contro-l grid coaxially mounted at one end of said cathode to produce when charged longitudinal deiiection of said emission, an anode of a U shaped cross-section located at the other end of said emission element, and means to permit only a concentrated stream of electrons to reach said anode.

26. An electron discharge system comprising, a cathode member, an accelerating and control electrode located adjacent one side of said cathode member, and an anode located at the other side of said cathode member.

27. A thermionic tube comprising a cathode, including an elongated electron emission portion one end of which terminates in .a shield portion, an accelerating and control grid coaxially mounted at one end of said elongated emission portion, and an anode coaxially located at the other end of said cathode emission portion adjacent said shield portion.

28. A discharge device comprising an elongated cathode from which emission takes place, an accelerating electrode located at one end of said cathode, an anode located at the other end of said cathode, and means for applying potentials to said accelerating electrode cathode and anode-such that the distance traveled by each electron emitted from said'cathode to said anode times the rate of travel is equal to a constant.

29. Al relay system comprising an electrical discharge devicehaving elongated means which when heated produce diffused emission of'electrons, a control member, a circuit including a source of direct current between said means and member, said member being adjacentone end of said means and-having a surface the distance of which from said means varies whereby the acceleration imparted to the electrons by said member decreases as the distanceV between said means -andmember increases, and a circuitconf nected between said means and said member for 

